因式分解:
8(c+2d)的平方-50(3c-d)的平方
點做好??!
中三Maths 一問
2007-10-02 2:44 am
回答 (2)
2007-10-02 2:58 am
✔ 最佳答案
8(c+2d)^2-50(3c-d)^2 =2(4(c+2d)^2-25(3c-d)^2)
=2[ {2(c+2d)}^2 - {5(3c-d)}^2 ]
=2 {2(c+2d)+5(3c-d)} {2(c+2d)-5(3c-d)}
=2(17c-d)(-13c+9d)
=-2(17c-d)(13c-9d)
2007-10-02 3:01 am
8(c+2d)^2-50(3c-d)^2
=2(4(c+2d)^2-25(3c-d)^2)
=2[ {2(c+2d)}^2 - {5(3c-d)}^2 ]
=2 {2(c+2d)+5(3c-d)} {2(c+2d)-5(3c-d)}
=2(17c-d)(-13c+9d)
=-2(17c-d)(13c-9d)
=2(4(c+2d)^2-25(3c-d)^2)
=2[ {2(c+2d)}^2 - {5(3c-d)}^2 ]
=2 {2(c+2d)+5(3c-d)} {2(c+2d)-5(3c-d)}
=2(17c-d)(-13c+9d)
=-2(17c-d)(13c-9d)
收錄日期: 2021-04-24 00:31:43
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071001000051KK04420